1. Field of the Invention
The present invention relates generally to a teletex and videotex processing system. More specifically, the present invention relates to a teletex and videotex processing system which can concurrently process teletext (hereinafter referred to TTX) transmitted through a wireless network and a videotex transmitted through a telephone network. A corresponding TTX-videotex processing method is also disclosed.
Korean Patent Application No. 93-14182 is incorporated herein by reference for all purposes.
2. Description of the Related Art
In conventional TTX systems, the necessary information can be obtained by extraction of digital data loaded and transmitted via a broadcast signal. Accordingly, the conventional TTX has an advantage whereby the user can easily and freely obtain information. On the other hand, with TTX, the user himself (or herself) does not have an opportunity to select the information since the information transmission is made in an one-way direction, i.e., from a broadcasting station to the user.
In conventional videotex, the necessary information can be obtained by extraction of the data transmitted through a telephone network. Accordingly, a bi-directional information transmission can be made with videotex. However, the user of the videotex system is charged for transmitting the information and much time is required for obtaining the information. U.S. Pat. No. 5,093,902 issued on Mar. 3, 1992, entitled "MEMORY CONTROL APPARATUS FOR ACCESSING AN IMAGE MEMORY IN CYCLE STEALING FASHION TO READ AND WRITE VIDEOTEX SIGNALS" discloses a technique for performing a write or read operation of image data with respect to an image memory at a high speed by detecting the state of a central processing unit CPU and generating a wait signal to the CPU according to a detection result.
According to U.S. Pat. No. 5,093,902, an operation state detector receives a reference pulse generated by a timing signal generator and an access control signal output from the CPU detects the state of the CPU with respect to an access period. A wait signal generator generates the wait signal to the CPU according to the detection result from the operation state detector. A display controller receives a command from the CPU during the access period set by timing-dividing of a display period, and controls the write or read operation of the image data with respect to the image memory, thereby performing the data transmission between the CPU and the image memory at a high speed.
In machines adopted to perform this technique, it is possible to read and store the videotex data or TTX data at a high speed by controlling the CPU. However, it is impossible to carry out concurrent videotex and the TTX data processing using one system.